"An international team of paleontologists from China and the United States has found high levels of mercury in the end-Permian marine sediments at nearly a dozen sites around the world, which provides persuasive evidence that volcanic eruptions were to blame for the mass extinction at the end of the Permian period.
....known as the Permian-Triassic extinction event and the Great Dying, is the largest mass extinction event in Earth’s history.
The catastrophe killed off nearly 96% of all marine species on the planet.
The main cause of the extinction is generally thought to be linked to
perturbations caused by eruptions in a volcanic system called the Siberian Traps.
Many of the eruptions occurred not in cone-shaped volcanoes but through gaping fissures in the ground.
The eruptions ignited vast deposits of coal, releasing mercury vapor high into the atmosphere. Eventually, it rained down into the marine sediment around the planet, creating an elemental signature of a catastrophe.
“Volcanic activities, including emissions of volcanic gases and combustion of organic matter, released abundant mercury to the surface of the Earth,” said study lead author Dr. Jun Shen, a researcher at the China University of Geosciences..jpg)
The researchers used the sharp fossilized teeth of lamprey-like creatures called conodonts to date the rock in which the mercury was deposited. Like most other creatures on the planet, conodonts were decimated by the catastrophe.
The eruptions propelled as much as 3 million km of ash high into the air over this extended period.
“In fact, the Siberian Traps eruptions spewed so much material in the air, particularly greenhouse gases, that it warmed the planet by an average of about 10 degrees centigrade,” Professor Algeo said."
SciNews
Many of the eruptions occurred not in cone-shaped volcanoes but through gaping fissures in the ground.
The eruptions ignited vast deposits of coal, releasing mercury vapor high into the atmosphere. Eventually, it rained down into the marine sediment around the planet, creating an elemental signature of a catastrophe.
“Volcanic activities, including emissions of volcanic gases and combustion of organic matter, released abundant mercury to the surface of the Earth,” said study lead author Dr. Jun Shen, a researcher at the China University of Geosciences.
.jpg)
The researchers used the sharp fossilized teeth of lamprey-like creatures called conodonts to date the rock in which the mercury was deposited. Like most other creatures on the planet, conodonts were decimated by the catastrophe.
The eruptions propelled as much as 3 million km of ash high into the air over this extended period.
“In fact, the Siberian Traps eruptions spewed so much material in the air, particularly greenhouse gases, that it warmed the planet by an average of about 10 degrees centigrade,” Professor Algeo said."
SciNews
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